This guide suggests how to change the timing belt about every 60,000 miles (97,000 km) which has neither come off nor skipped badly, and also change the water pump located behind the timing cover and below the OHC (overhead cam) cover which both must be removed. The timing belt and its tensioner and idler must be removed (and install a new water pump unless it is new; how and why is explained.)

Edited data* this is a non-interference motor not interference.

This repair is rather difficult (patience, time and mechanics' tools are required, see things you'll need at the bottom of this article), but this can save you up to or over $1,000 if everything went right (that depends on not forgetting to replace or tighten or even accidentally breaking a bolt.) You still have the expense of the parts up to $300 (from auto parts store, USA -- new: auxiliary belts, timing-belt plus the tensioner and idler pulleys and water pump) and probably upwards of $600 or more from a the OEM (original equipment manufacturer) parts dealer. Follow the steps carefully and double check all the removal, installation and reassembly steps including carefully tightening bolts -- checking and rechecking all work as you go.

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Steps

1

Obtain a manual, and check and it should have torquing instructions for bolts and compare their instructions to this and follow any recommendations about removal, installation and replacement instructions, pictures and diagrams that may be helpful. The owner/operator guide omits such repairs. The factory Mazda, OEM, repair manuals do not explain in detail for a beginner and advise use of unnecessary tools. (The tools needed will be mentioned in each step.) Check the manuals and see which of these cars used this same engine -- some up to 2004.

Caution: Use the "smallest workable ratchet, breakover wrench and/or cheater leverage extension" correctly to not over tighten (over torque) bolts and avoid breaking off a bolt or screw (more detail in the "Warnings Section").

You actually might have to remove the engine to extract a broken bolt when you do the reassembly if you break off a screw or bolt in a tight spot for instance.

2

Avoid engine damage from the timing belt breaking or slipping, or the tensioner pulley or idler pulley locking up (seizing) or the timing belt skipping one or more cogs on a sprocket causing valve timing problems and possibly breaking valves, pistons and/or the engine cylinder (block):

Diagram shows both halves of the timing covers, belt, a large thin washer behind the harmonic pulley is a guard for the crankshaft opening in the lower half timing cover, retaining bolt for the harmonic pulley.

Change the timing belt, timing belt tensioner and its idler pulley.

Caution: this is an interference engine meaning that the valves and pistons will come into contact, interfere and damage or ruin the engine in case (if) the timing belt were to break or slips on cam(s) sprockets or the crankshaft sprocket (more detail in the "Warnings Section").

3

Understand the numbering of the cylinders and label the spark plug cables and cylinders 1, 2, 3, 4 from left to right but the other end is not that easy and carefully pry and get the cables off their spark plugs.

4

Check your manual for firing order which will be 1, 3, 4, 2 or such for 1993--1997 (verify this carefully) and 1, 4, 3, 2 or such for after 1998 for how they plug onto the coil pack or distributor on older models.(Storer, J, and Haynes, John H, (1999, 2001), Mazda 626 and MX6 Ford Probe Repair Manual, ISBN 1-56392-440-4)

Caution: Disconnect the negative battery terminal, so your engine can not be accidentally turned or started in error, you must remove the spark plugs before doing dangerous work.

5

Drain all the coolant from the engine and keep it to use again or dispose of it legally; no matter how little.

6

Remove both of the accessory belt(s) for the alternator and power steering, etc:

The older models with two belts have lock bolts on the tensioner bolts that must be loosened before you can turn the long tensioner bolt. You will need to loosen the lock bolts a turn or more and then loosen the tensioner a good number of turns until you can get enough slack to remove the belts.

7

Remove the bolts holding the power steering pump by unbolting the 3 bolts to release the power steering pump bracket from the engine (12mm and 14mm), but without opening or unsealing the power steering hoses or you will need to drain it and refill it when finished. This will help get some working space, where it is difficult to loosen and tighten the lock bolt on the power steering tensioner with a combination wrench (14mm) even by switching ends of the wrench. Do not pry belts off or on.

8

Loosen the long bolt of alternator pivoting bracket on the alternator belt; so it will allow the adjustable accessory to pivot as tension is released, loosen the tensioner enough to remove the belt. The older models do have two flat belts (not v-belts) and the newer models probably have a single serpentine belt.

Do not pry or force the belts to get them off; you will probably need it all loosened even more to get the new tighter belts on anyway.

9

Follow serpentine belt instructions in your operator manual and see their diagram for that kind of belt, if so equipped on newer models.

Method1

Remove spark plugs, harmonic pulley, valve cover

1

Remove two short 10mm bolts (all bolts should be hex-head, unless some newer models use Torx/Star bolt heads) holding the power steering hose on where it crosses the valve cover and work the hose toward the left out of the way for removing the valve cover in a later step. One of the 10mm bolt that will be removed later was covered (hidden) but is now "found" under that hose.

2

Remove spark plugs use a spark plug socket with a rubber grommet inside the socket so that it helps to lift plugs them out of the deep access ports. Or you could get them up from the ports if you find a way to use a piece of hose inserted snugly over each spark plug after each is unscrewed.

Do this carefully to keep from breaking or dropping the spark plugs especially if you want to reuse them.

3

Prevent dirt, trash or any screws (or ceramic-glass pieces if you broke a spark plug) from falling into the cylinders any of which could cause very serious damage to the engine.

4

Loosen the harmonic pulley (but do not remove it at this time) retainer bolt (21mm, 13/16 inch) but keep it in but "finger-tight" (snug). You use a small but powerful impact wrench to loosen it.

5

Consider using the power of the starter motor (only with the spark plugs taken out -- not holding the wrench by hand or foot).

With the spark plugs out, you would then reconnect the battery for just the next few moments to cause a very little "bump" of the starter motor by a momentary bump of a "remote push-button starter switch" or by wiggling the ignition switch to "nudge and thump" the pulley bolt a very small amount (bump) while a socket wrench (not held by hand or foot) is lodged onto the bolt as explained below.

Caution: do not hold the wrench by hand if you are power bumping it loose with the starter motor. To do that position a breakover wrench with about 2.5ft (75cm) cheater pipe (like 1 or 1.5 inch steel conduit tubing) extending it and positioned at about a 45 degree angle down toward the front of the car to be held firmly against the floor or earth, blocked in place with large stones, or by being inserted in an opening of a concrete block and blocked in and about by heavy toolboxes to keep the cheater from sliding out or from side to side -- but no hands or feet trying to hold it.

6

Bump the ignition switch (turn momentarily) to make starter motor "bump." Then see whether it loosened the bolt--but if not then check that its still on correctly and lined up and try it again. It may loosen on the first two or three tries, when it loosens enough you'll probably hear a something like a little "zinging/whizzing" sound. So don't have loud music/talk, etc. -- beware, aware.

Caution: Disconnect the negative battery terminal again after this technique so your engine can not be accidentally "bumped" or turned away from TDC by the starter motor in error.

Method2

Timing marks, align timing, accessory belts,

1

There or two of these cam shafts. Be careful not to disturb or damage them while working around them.

Barely loosen (break loose) each of the 11 bolts (10mm) connecting the OHC (overhead cam) valve cover to the engine. Loosen the 9 bolts around the edge of the cover that connect it to the block (one in on the very end). Two of those 10mm bolts are upon the cover with one about 3 times longer and (it was covered up by that power steering hose) and the one in the center is about 4 times longer than the ones around the edges. Once all are just loosened then finish removing them.

2

Remove the OHC cam valve cover which is necessary to access the timing belt, the top of the timing belt sprockets, and the cam timing marks.

3

Do not turn the engine using the cam timing sprockets or their retaining bolts, or by pulling on the timing belt. The engine should be easy to turn with a socket wrench on the crankshaft bolt since the spark plugs are out and all pressure is released.

4

Align the timing marks on back of the cam sprockets lined up straight across, with a wrench on the retaining bolt of the harmonic pulley

Caution: with the negative terminal of the battery disconnected). aligned with the top of the engine head while at the same time you line up the timing mark on the crankshaft harmonic pulley pointing straight up at the same time as the cams are aligned (or use the crankshaft key and slot later in the process when the harmonic pulley is off).

Caution: the TDC (top dead center) could be 180 degrees off of the correct TDC even when the crankshaft mark or crankshaft key is correctly pointing straight up ("It would then be at the top of the exhaust stroke."); so then align it as explained next.

Caution: check timing is at the correct TDC (top dead center of the compression stroke) and find the marks are on the back of the sprockets and align them with the edge of the engine head. The older models have a distributor and you can remove the distributor cap to see if it is pointing at spark plug cable terminal number one (for cylinder number 1) when the mark on crankshaft pulley shows it is at TDC. If it points to the opposite side of the distributor then turn the engine slowly 360 degrees on the crankshaft to be back around to TDC ("top of the compression stroke"). Newer engines do not have a distributor and so the correct TDC can be found while the harmonic pulley timing mark is approaching TDC. This is done using the compression stroke air pressure measured in the "number one spark plug hole" by a "compression gauge" to know when the piston is on the compression stroke and then turning slowly and carefully to exactly the TDC as shown by the crankshaft and the cam sprockets timing marks. Compression pressure means that the piston in cylinder one was on the compression stroke not the exhaust stroke which also comes to TDC.

Required: securely place a "plastic/rubber" stop-block (you may use a bottle stopper from a wine bottle preferably "not real cork" which might crumble) to put it in place to jam the cam sprockets with the "rubber stop-block." Use the stop-block before releasing the tensioner pulley to remove the timing belt, or else when the timing belt is removed the cams will "turn" (in opposite directions) about two notches--pushed by the valve springs pressure off TDC of the cam lobes. Later before the timing belt is re-installed use two "open-end" wrenches or adjustable spanners for 1 inch (25.5 ~ 26mm) on the hex part of the camshaft (not on the sprocket bolt) to slightly nudge the sprockets back and forth (small wiggling) to get the stop block to hold both cam marks correctly aligned while the stop-block is between the two cam sprockets. So it holds both cams at the same time in TDC position (You may purchase a special stop-block made for this purpose if you prefer.).

5

Work on level ground and block the wheels (so they won't roll) with bricks or wooden pieces about the size of a bricks. Put on the parking brake.

6

Loosen the right front wheel lug nuts but leave them snug ("right side" as when you are seated in the car).

7

Jack up that side of the car. Then use a jack-stand to support the car. Do not depend on the jack to support it. You will be removing the wheel adjacent to (next to) the pulleys only.

8

Realize that later you will support the engine separately with a jack as explained when it is needed but you may need a different jack.

9

Remove the plastic splash-guard cover under the engine which extends to cover the side of the wheel well. Watch your head.

10

Support the engine securely but with just little/slight upward pressure with a "scissor jack" or "bottle jack" with a strong piece of wood (longer than a brick) to protect the engine from the jack. It should work under the air conditioner bracket which is massive on the older models. The engine being supported is because you will remove (not yet) the motor mount in steps when you get to it in a later step; that mount is between the top and lower halves of the timing-cover and is very much in the way of working on the accessory belts, timing belt and water pump.

11

Remove the plastic top half timing-cover which is held on by 4 small bolts (10mm), with one near each corner. The two toward the firewall of the auto are difficult to reach and even to see. Use a short, small ratchet drive extension.

12

Remove the "harmonic pulley bolt" (21mm) that you had loosened earlier and remove the pulley. You probably can wiggle and jiggle the pulley while start gently prying and pulling it off the crankshaft. If not, then you may need to use a steering wheel puller or similar puller.

13

Put the bolt back in to hold the sprocket on and be sure the sprocket "key" is always kept in its slot. This was necessary to be able to remove the lower timing cover.

14

Remove the retaining screws from the lower half timing cover (10mm). One screw is hard to see in the middle of the cover, right below the motor mount.

15

Remove the lower timing cover carefully because you have to maneuver it to clear off of the sort of alignment pin-block (actually almost a little cube and is about 2cm) and is just above the crankshaft sprocket and fits into a place in the lower half cover but you can not see it until the cover is off.

Method3

Remove engine mount

1

Be sure to also support the engine with a jack just putting a little pressure upward so you can prepare to remove the motor mount on the belt end of the engine.

2

Begin removing the motor mount by unbolting the 7 bracket bolts (17mm = 11/16 inch) with a strong breakover wrench with a cheater pipe on its handle to get more leverage and remove an 8th bolt which is the longer bolt that passes through the middle of the lumpy looking metal-rubber mount also.

3

Find the "seventh" bracket bolt if not yet removed which was uncovered when you lifted out the heavy lump-like middle part of the mount.

4

Remove the huge, oddly shaped motor mount bracket carefully from among the air conditioning hoses and power steering hoses by pulling them back "just a little," and yet do not damage the wiring and hoses.

5

Remove the smaller "engine mount bracket" of the motor mount which is heavy duty steel and is still bolted to the engine block after you have removed the rest that was mounted to the fender area. You'll need the 17mm socket and a 3/8 inch ratchet with smaller cheater extension to loosen the bolt. 1/2 inch ratchet is hard to use between things in the tight areas. It is rather awkward to do.

Method4

Install New Timing Belt, New Tensioner, Idler, and the Water Pump

1

Readying to remove the timing belt, you need to turn the timing belt tensioner pulley toward "counter-clockwise" with an Allen "L-shaped" hex tool that fits in a hole in the pulley to rotate it to be able to slip the belt off little by little.

2

Turn (pivot) the timing belt tensioner pulley toward "clockwise" with the Allen hex wrench enough to take the tension off of the timing belt tensioner spring and then remove the spring with very long-nose-pliers.

3

Remove the tensioner pulley by one bolt in the middle (14mm).

4

Remove the "idler" pulley of the timing belt system (14mm).

5

Remove the 4 or 5 water pump bolts which are hard to see -- (12mm) socket -- and a medium size ratchet (called 3/8 inch drive in the USA). Be careful because one bolt that is easier to see looks like it may be one to remove but its left of the correct one) and find and then loosen the water pump. Loosen it from the block by tapping it with a wooden block and a mallet hammer but if it does not come loose pretty easily --check again for another bolt.

6

Clean the engine block surface carefully where the water pump gasket will make contact for sealing well -- so carefully scrape off any pieces of stuck-on old gasket material corrosion, rust, or dirt to bare metal without gouging or roughing the metal.

7

Put on the "new water pump"; follow instructions that came with it. Tighten 12mm bolts securely without over-tightening, ie: breaking one off. Seal the new gasket only onto the new pump with "gasket cement." Do not cement it onto the block. Put anti-seize grease on bolts. You can put an even coating of marine grease on the gasket after it is cemented onto the pump so it will not stick to the engine block.

Or if you prefer to use a silicone gasket maker then apply a small even bead but not an excessive amount that could squeeze out and cause plugging/blockage of coolant passage ways in the engine or radiator.

8

Install the "new timing tensioner" pulley and tighten its mounting bolt securely. Hook the new spring in the hole of the tensioner ear/tab and use the Allen wrench in the hole that is in the front surface of the tensioner pulley for that wrench to bring the spring clockwise to get the spring near and then hooked onto the pin that protrudes from the engine block just above the pulley,

9

Install the new "idler pulley" and tighten the mounting bolt securely.

10

Keeping the stop block in place to hold the sprockets aligned, Start the belt part way onto the "crankshaft pulley sprocket" and going counter-clockwise being certain to place the belt without slack onto the left of the idler pulley and across the tops of the "cam sprockets" and use the Allen Wrench to rotate the tensioner toward counterclockwise to get the belt on to the right of the tensioner, and work the belt the rest of the way onto the sprockets and both pulleys.

Put on the "new timing belt"; follow instructions that came with it. (Like a 1 inch (25.5 ~ 26mm) open end wrench can be used to budge the cam slightly to get a cam timing mark back aligned while keeping the stopper "jammed" (in to hold the sprockets) in place until you get the belt on and the tension spring on right. So, starting at the crankshaft sprocket place the belt a little more than halfway onto the sprocket and then going counter-clockwise making sure the belt is tightly against the idler pulley/roller as you slip the belt onto the cam sprockets and tight across between the cam sprockets when on both of them.

11

Press the timing belt onto place while keeping the tensioner pulley out of the way using the Allen hex wrench toward counterclockwise for the pulley to be as far backed off as possible to allow the belt to slide on to the sprockets. While holding that hex wrench begin to work the belt in steps farther onto each sprocket until it is on all the way.

12

With the Allen wrench in the hole in tensioner pulley for that purpose press it toward clockwise against the belt and press it in for a little tightening of the belt, and then release it slowly for the spring to bring it back into position.

13

Remove the "stopper block" from the cams -- before you put on the top half-cover on the timing belt area.

Hand rotate the crankshaft two times around using a wrench on the crankshaft sprocket bolt, then check to see that when the crankshaft key is aligned, then the two cam timing marks are still aligned as described earlier. Be sure one or both isn't off by one notch or something. If it not aligned properly then remove the belt, carefully realign all 3 marks and reinstall the belt, and double-check it again.

Method5

Reassemble

1

Assemble parts mostly in reverse order of the removal and tighten bolts properly.

2

Install "lower-half cover" of the timing belt and put the bolt and especially the one in the middle which is hard to see just below the motor mount bracket.

3

Remove the big bolt for a moment from the crankshaft sprocket to then put on the crankshaft pulley.

4

Put the harmonic crankshaft pulley on be sure the pulley key slot aligns on the slot and key of the crankshaft that must be aligned into the slot in the pulley. Put the big bolt back with the washer/disk and tighten it securely.

Tighten and torque the harmonic crankshaft pulley bolt while you hold the pulley with a bar between bolts placed in the "puller bolt holes" of the pulley, or as best you can hold it without damaging it, and torque it to about 115 feet (35.1 m) lbs..

5

Install only the third part of engine mount (the smaller bracket) that bolts to the engine block (for now) -- because it will be partly covered by the timing covers. Use the large ratchet or medium sized ratchet (3/8 inch) with a cheater extension to tighten the motor mount bracket securely and also to reinstall the other parts of the motor mount later (before you remove the jacks).

6

Reassembly is mostly in reverse order of the removal of course such as the bottom and then top half timing covers, the alternator belt, power steering bracket and belt, adjust the those belt tensions, put on OHC valve cover

7

Install spark plugs with the spark plug cables in the correct order.

8

After all the miscellaneous reassembly is done, now install the motor mount bracket securely with its 3 bolts and 2 nuts onto the car fender and the motor mount itself with the long bolt and nut and 2 nuts that attach it to studs on the part of the bracket that is attached to the engine block. You will need to pull a little on the hoses and move the wiring around to work the big mount bracket into its place and yet not damage the wiring and hoses. It's tricky, so be patient.

9

Replace the under engine/wheel-well side cover and put on the wheel but re-tighten it after it is on the ground, later.

10

Prepare to remove the engine supporting jack, by first verifying that the motor mount brackets and motor mount are installed and all the bolts are tightened, raise the car a little and remove the jack stand and lower the car, and remove wheel chock blocks. Almost finished.

11

Remove the "radiator cap" and refill the radiator with coolant (note: some cars have a remote tank with a cap but no radiator-cap.) and then refill the coolant system and refill the overflow tank, bounce the car on the side where it is not on the jack and add more coolant; do that a few more times. Check for coolants leaks.

12

Clear away any tools, etc. before starting the engine.

13

Reconnect the battery negative cable.

14

Check for coolant leaks, check all other fluids, and leave the radiator cap off temporarily to recheck so you can top-off the coolant level after starting the engine.

15

Let it idle while finishing filling with coolant and put on the radiator cap, and be sure that the car is otherwise road worthy.

Community Q&A

It probably has a bent valve. Not an easy fix from there. Ford Probes have a zero interference engine which means if a belt breaks or timing is off, a piston will hit the valve and bend it and or put a hole in the piston. Local parts stores lend out a tool to check compression.

Tips

You should get a good repair manual with pictures to help you with this. It may not have very detailed instructions, but pictures and labeled parts in the pictures and their recommended order of the processes may be very helpful.

It is important to remember where various sizes and lengths of bolts came from (go back in) and the tool that you had to use.

Keep bolts together for each part and remember the tool(s) that you needed for the dis-assembly.

Breakover wrench is used to "break loose" the tight bolts and to not break your ratchet instead.

Put unused tools away to keep down clutter and confusion.

Recalling how your fingers and a wrench barely fitted into tight spaces and how you maneuvered them for dis-assembly will help you reassemble in problem areas.

Do not use this guide as your only reference. You may encounter issues or problems not covered in this article.

This repair is involved (complicated). If you are not a fairly experienced mechanic, consider taking it to a shop -- or get good helper who will spend several hours actually working.

It would take less time if one of you were experienced.

If one of you has smaller hands (and/or longer fingers) to reach into tight spaces to insert screws and if the helper is pretty sure of how to do it -- all of that will help greatly.

Warnings

Disconnect the negative battery cable and the spark plug cables at the spark plugs before putting your hands in dangerous places or doing any removal of moving parts or their covers or even brackets.

Coolant (antifreeze) is poisonous to fish, unsuspecting animals and children because it looks, smells and tastes good, but it is lethal/deadly. It should be stored or disposed of properly as a hazardous chemical.

Caution: if you remove the spark plug cables completely then understand that firing order is "not" 1,2,3,4, but may be 1, 3, 4, 2 and so first appropriately number and label on or next to the "mixed up" ignition coil pack terminals (or distributor on older models) with the correct cable number -- and start replacing them at the correct terminal or plug on the coil pack/distributor.

It is very important to be perfectly in that special order. Numbers may be formed or stamped on OEM equipment, but may not be on after market parts.

You actually might have to remove the engine to extract a broken bolt if you break off a screw or bolt in a tight spot when you are tightening them.

Avoid breaking off a screw or bolt during reassembly by using small, medium and large ratchets correctly (use the smaller ratchet that will do the job to not over torque small and medium bolts) to get the parts tightened adequately -- but a broken bolt would have to be drilled (like hollowed out) and then an extractor tool used); so use the:

1/4 inch ratchet for small bolts (like 8, 9 or 10mm) to not break them off,

3/8 inch ratchet for medium sized bolts (12, 14 or 15mm) to not break those (consider using this one with a "1/4 inch adapter" for small bolts because the adapter may break before the bolt; you hope.)

1/2 inch ratchet for larger sized bolts (17mm, etc.) to adequately tighten but not break those (the ratchet names are what they are called in the USA).

Decide if a torque wrench is desirable or necessary -- and it is recommended -- to more accurately tighten bolts (if you decide that you need that kind of help) to check the tightness without over tightening.

3/4 inch breakover ratchet would not be needed for this repair except "optionally" on the retaining bolt (21mm, 13/16 inch) on the harmonic crankshaft pulley.

Why should you change the water pump when you change the timing belt and its pulleys ("unless" it were changed very recently) -- that's because the rubber seal of the water pump (as with the rubber timing belt and seals of the timing pulleys) gets brittle from engine heat, repeatedly heating and re-cooling and just getting old.

Also, that water pump replacement (and timing pulley too) is because bearing grease dries out and the bearing locks up (seizes) if the water pump and timing belt pulleys are not changed periodically.

There is no way to re-lubricate the bearing (sealed up and "permanently" lubricated) -- just waiting to fail (dry out, burn out and lock up).

Things You'll Need

Stop-block for the cam sprockets

New timing belt with matching new tensioner and idler pulley

New water pump, gasket and gasket cement

New accessory belts

Repair manual covering your car model, for this engine

Small, medium and large ratchets (called 1/4, 3/8 and 1/2 inch in the USA)

Torque wrench to more accurately tighten bolts (if you need that kind of help)

Sockets, not many deep sockets except to reach odd places and on the motor mount stud (17mm, 11/16 inch)